serve target client: Ensure repository key blob is also in remote CAS

4 files changed, 20 insertions, 5 deletions

diff --git a/src/buildtool/build_engine/target_map/absent_target_map.cpp b/src/buildtool/build_engine/target_map/absent_target_map.cpp
index 3ceaa4d8..6d41f182 100644
--- a/src/buildtool/build_engine/target_map/absent_target_map.cpp
+++ b/src/buildtool/build_engine/target_map/absent_target_map.cpp
@@ -74,7 +74,8 @@ auto BuildMaps::Target::CreateAbsentTargetMap(
             Logger::Log(LogLevel::Debug,
                         "Querying just serve for export target {}",
                         key.target.ToString());
-            target_cache_value = ServeApi::ServeTarget(*target_cache_key);
+            target_cache_value =
+                ServeApi::ServeTarget(*target_cache_key, *repo_key);
             from_just_serve = true;
         }
 
diff --git a/src/buildtool/serve_api/remote/serve_api.hpp b/src/buildtool/serve_api/remote/serve_api.hpp
index 16b998b4..fce7611d 100644
--- a/src/buildtool/serve_api/remote/serve_api.hpp
+++ b/src/buildtool/serve_api/remote/serve_api.hpp
@@ -69,9 +69,10 @@ class ServeApi final {
             target_root_id, target_file, target);
     }
 
-    [[nodiscard]] static auto ServeTarget(const TargetCacheKey& key)
+    [[nodiscard]] static auto ServeTarget(const TargetCacheKey& key,
+                                          const std::string& repo_key)
         -> std::optional<std::pair<TargetCacheEntry, Artifact::ObjectInfo>> {
-        return Instance().tc_->ServeTarget(key);
+        return Instance().tc_->ServeTarget(key, repo_key);
     }
 
     [[nodiscard]] static auto CheckServeRemoteExecution() -> bool {
diff --git a/src/buildtool/serve_api/remote/target_client.cpp b/src/buildtool/serve_api/remote/target_client.cpp
index 8571910d..7166a604 100644
--- a/src/buildtool/serve_api/remote/target_client.cpp
+++ b/src/buildtool/serve_api/remote/target_client.cpp
@@ -25,7 +25,8 @@ TargetClient::TargetClient(std::string const& server, Port port) noexcept {
         CreateChannelWithCredentials(server, port));
 }
 
-auto TargetClient::ServeTarget(const TargetCacheKey& key)
+auto TargetClient::ServeTarget(const TargetCacheKey& key,
+                               const std::string& repo_key)
     -> std::optional<std::pair<TargetCacheEntry, Artifact::ObjectInfo>> {
     // make sure the blob containing the key is in the remote cas
     if (!local_api_->RetrieveToCas({key.Id()}, &*remote_api_)) {
@@ -34,6 +35,16 @@ auto TargetClient::ServeTarget(const TargetCacheKey& key)
                      key.Id().ToString());
         return std::nullopt;
     }
+    // make sure the repository configuration blob is in the remote cas
+    if (!local_api_->RetrieveToCas(
+            {Artifact::ObjectInfo{.digest = ArtifactDigest{repo_key, 0, false},
+                                  .type = ObjectType::File}},
+            &*remote_api_)) {
+        logger_.Emit(LogLevel::Error,
+                     "failed to retrieve to remote cas blob {}",
+                     repo_key);
+        return std::nullopt;
+    }
 
     bazel_re::Digest key_dgst{key.Id().digest};
     justbuild::just_serve::ServeTargetRequest request{};
diff --git a/src/buildtool/serve_api/remote/target_client.hpp b/src/buildtool/serve_api/remote/target_client.hpp
index 72b8d82c..9219fb3d 100644
--- a/src/buildtool/serve_api/remote/target_client.hpp
+++ b/src/buildtool/serve_api/remote/target_client.hpp
@@ -38,8 +38,10 @@ class TargetClient {
     /// \brief Retrieve the pair of TargetCacheEntry and ObjectInfo associated
     /// to the given key.
     /// \param[in] key The TargetCacheKey of an export target
+    /// \param[in] repo_key The RepositoryKey to upload as precondition
     /// \returns Pair of cache entry and its object info on success or nullopt.
-    [[nodiscard]] auto ServeTarget(const TargetCacheKey& key)
+    [[nodiscard]] auto ServeTarget(const TargetCacheKey& key,
+                                   const std::string& repo_key)
         -> std::optional<std::pair<TargetCacheEntry, Artifact::ObjectInfo>>;
 
     /// \brief Retrieve the flexible config variables of an export target.